Plaster-of-paris cutter



G. H. DESROCHE RS.

PLASTER 0F PARIS'CUTTER. APPLICATION FILED MAR-.2, 1920 Patented Fe b..1 5, 1921.

d w W M p INVENTOI Qr ATTORNEY.

WITNESS.-

.omrsstares rarsnr OFFICE.

GEORGE H. DESROCHERS, OE LOWELL, MASSACHUSETTS.

PLASTER-OF-PARIS CUTTER.

' Application filed March 2,

T 0 all whom it may concern:

Be it known that I, Gnoncn H. Dnenoormns, a citizen of the United States, residing at Lowell, in the county oi Middlesex and Commonwealth of Massachusetts, have invented a certain new and useful Tmprovement in Plaster-of-Paris Cutters, of which the following is a specification.

This invention relates principally to plaster of Paris cutters or shears adapted to cut and break the plaster casts or jackets in which surgeons and physicians secure broken and dislocated limbs or displaced parts after setting the same. Said invention is applicable, however, to other hand operated cutters and shears requiring great power.

Such casts and jackets are made of plaster of Paris laid over an: inner bandage of fibrous or textile material, as cotton wadding, and being applied in a plastic condition become very hard and require for removal the use of metallic instruments and considerable muscular force, and frequently a previous softening of the cast by the use of vinegar or acid.

The instruments most commonly used for removing the plaster are knives, as jackknives, or shoemakers knives, which are drawn over the plaster to form grooves or scores by means of which the plaster may be more easily broken. Sometimes a canopener is used for removal of the plaster. Of course, the patient is liable to be cut in the operation, which sometimes lasts for hours and fatigues the operator and the patient and is expensive for the patient.

The object of this invention is to increase the efficiency of the applied force and save time of the surgeon, and to avoid injury, expense and fatigue to the patient, and the use of vinegar or acid. 7

In the accompanying drawings, Figure 1, is a side elevation of a plaster of Paris cutter embodying my invention, the end-portion of the handles proper being broken away; and the jaws being closed; Fig. 2, a cross-section of the base handle, showing the joint which connectssaid handle to the operating lever; Fig. 3, a cross-section of the sliding fulcrum on the line 3 3 in Fig. 1; Fig. i, a side elevation of the cutter open.

A indicates the base handle or lever which in-actual cutting is stationary, but is used Specification of Letters Patent.

Patented Feb. 15, 1921.

1920. Serial No. 362,671.

to crowd the cutters forwardfor a now out.

Integral with the handle A or rigidly secured thereto is the upper stationary female cutter a having anupwardlyflaring open- 111g to receive the lower movable male cutter E and prevent lateral inovementofthe same.

The cutter E is guided partly by a pin a passing through the sides of the cutter a and through a slot 6 in said cutter E, and partly by its connection with the intermediate lever C.

The cutter E 'isrprovided' with an upwardly extending arm 6 the upper end of which is jointed or pivoted at o tota short arm 0 of the intermediate lever C which is fulcrumed at a on the base handle A.

The slot 6 in the movable cutter E is preferably so arranged as shown in Fig. 4, and

the path of the pivot c is such that the angle between the straight cutting surfaces of the cutters will be substantially constant, to permit of continuous shearing. The lower end of said slot also acts as a stop to pre: vent the movable cutter from entering the stationary cutter farther than necessary.

One of the cutters, preferably the stationary cutter a is provided with notches a n the surface which contacts with the work to prevent the cutters from slipping off the cast while shearing.

The free end of the intermediate lever C is jointed to a sleeve or slide D which surrounds and moves freely on the operating lever or handle B.

Said slide D is provided with trunnions a (Z which turn freely in plates (Z d rigidly secured to the free end of the intermediate lever C and extending below said lever C. Said slide D, as the cutters are closed, approaches the fulcrum a of the operating lever and gives an increasing leverage to the latter with the same exertion of force, thus relieving the surgeon or operator.

cutters or jaws and allowing the cutter or jaw E to bep'ushed forward into the slit thus formed in order that cutting may be continued.

I claim as my invention:

1. A plaster of Paris cutter having in" combination a base-handle, a female cutter rigidly secured to said base-handle, amale cutter arranged and guided in said female cutter an intermediate lever fulcrurned on said base-handle and jointed to said male cutter, an operating handle fulcrumed on said base-handle, a sleeve sliding on-said' sleeve;

3. A plaster of Paris cutter having in combination a base-handle, a female cutter rigidly secured to said base-handle, a male cutter arrangedand guided in said female cutter an intermediate lever fulcrumed on said base-handle and jointed to said male cutter, an operating handle fulcrumed on said base-handle, a sleeve sliding on said operating handle, said sleeve having trun- -nions and plates secured to the free-end of said intermediate lever and having openings to receive said trunnions.

4:. A plaster of Paris cutter having in combination a base-handle, a female cutter rigidly secured to said base-handle, a male cutter arranged and guided in said female cutter an intermediate lever fulcrumed on said base-handle and jointed tosaidniale cutter, an operating handle fulcrumed on said base-handle, a sleeve sliding on said operating handle, means of forcing said cutters into operation, one of said cutters having notches to engage the Work and to prevent slipping thereon.

5. A plaster of Paris cutter having in combination a base-handle, a female cutter rigidly secured to said base-handle, a male cutter arranged and guided in said female cutter an intermediate lever fulcrumed on said base-handle and jointed to said male cutter, an operating handle fulcrumed on said base-handle, a sleeve sliding on said operating handle, means for forcing said cutters into operation, said female cutters having notches to engage the Work and to prevent slipping thereon.

GEORGE H. DESROCHERS. 

